CODEWITHSUNDEEP
vb.netlinq
yendang9423082
yendang9423082

Reputation: 365

How to group list of string using Linq?

I have list(of string) like this:

C:\Users\..\Documents\abc_1.1.pdf     ->file name abc
C:\Users\..\Documents\abc_1.2.pdf
C:\Users\..\Documents\abc_2.1.pdf
C:\Users\..\Documents\xxxxxx_1.1.pdf  ->file name xxxxxx
C:\Users\..\Documents\xxxxxx_2.1.pdf

How can I use linq and group these file into groups if file has same name.

such as ex above, I want to get 2 groups, so I use the following code:

listfile.GroupBy(Function(filepath) As String
                                      Dim filename = Path.GetFileNameWithoutExtension(filepath)
                                      Return Regex.Match(filename , ".+(?=_\d+\.\d+)").Value.ToString()
                 End Function)

But this return result is all files. Can I get collect subsets?

Upvotes: 0

Views: 345

Answers (1)

Mary
Mary

Reputation: 15101

I split the stings by the underscore and selected the first element. Then applied the Distinct method

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim lst As New List(Of String)
    lst.Add("C:\Users\..\Documents\abc_1.1.pdf")     '->file name abc
    lst.Add("C:\Users\..\Documents\abc_1.2.pdf")
    lst.Add("C:\Users\..\Documents\abc_2.1.pdf")
    lst.Add("C:\Users\..\Documents\xxxxxx_1.1.pdf")  '->file name xxxxxx
    lst.Add("C:\Users\..\Documents\xxxxxx_2.1.pdf")

    Dim newList = (From s In lst
                   Select s.Split("_"c)(0)).ToList.Distinct

    For Each s In newList
        Debug.Print(s)
    Next
End Sub

'Prints
'C:\Users\..\Documents\abc
'C:\Users\..\Documents\xxxxxx

Upvotes: 2

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